These unmanned aircraft systems are clearly capable of delivering contraband over prison walls. Furthermore, it's hard to spot them, much less find out who is controlling them.
Worse, when it comes to policing the problem at federal prisons, the U.S. Bureau of Prisons (BoP) is severely handcuffed. Despite having tons of shotgun-armed guards at its prisons, the bureau can't simply shoot down any drone that happens to appear near a prison; the Federal Aviation Administration doesn't allow it.
Guards can't blast drones with radio waves to interfere with the control signals from their operators either: Intentional interference of that sort is illegal, according to the Federal Communications Commission.
All of which is why the BoP has issued an RFI (request for information) looking for a solution.
The RFI — a preliminary step before the agency actually hires someone to implement a solution — is soliciting ideas that will help the BoP detect and neutralize drones trying either to conduct surveillance of prisons and the areas around them or to deliver contraband (such as weapons, drugs, or pornography).